• 스마트미디어저널
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• 제6권1호
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• pp.61-67
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• 2017

현 시대에 사는 사람들 중에 다수는 자의적이거나 타의적인 이유로 결혼을 하지 않거나 독립하여 혼자 생활하는 것을 선호하고 있고 그 이유로는 크게 타인에게 간섭받기 싫어서 또는 경제적 사정 등이 있으며, 특히 자신만의 편안한 생활을 추구하는 직장여성들이 일인 생활을 선호하는 추세이다. 하지만 이러한 점을 타겟으로 하여 악용하는 범죄의 표적이 되기도 한다. 그로인하여 현관문 등에 안전고리 등과 같은 보안장치를 추가 장착하여 사용하기도 한다. 현관문의 안전고리를 잠그는 행위는 그렇게 어려운 일은 아니지만 쉽게 잊어버릴 수 있고, 취침 전 잠자리에 위치하여 있을 때 안전고리의 잠금 여부를 확인하거나 잠가야할 때 다시 일어나서 현관으로 이동해 안전고리를 확인하고 잠가야 한다. 하지만 그 번거로움과 불편함으로 괜찮겠지 하는 마음에 안전고리를 채우지 않을 때가 많다. 본 논문에서는 이러한 번거로움을 해결하고 보다 안전한 생활을 유지하기위한 방법으로 스마트 폰을 이용하여 원격에서 안전고리를 조정할 수 있는 장치를 설계 및 구현하여 보다 편하게 안전고리를 사용하여 불법주거 침입 등의 범죄로 부터 안전을 도모 하고자 한다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2016년도 춘계학술대회
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• pp.241-243
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• 2016

과거, 자동차 보안은 'Door Lock'과 같은 물리적인 접근을 방지하는 것이었다. 그러나 시대가 발달함에 따라, 자동차 보안의 트렌드는 이러한 물리적인 보안에서 굉장히 지능적으로 바뀌었다. 이러한 변화는 해커들로 하여금 차량 통신 시스템을 공격할 계기를 만들게 되었고 현재 차량 통신 시스템은 몇 가지 취약점이 존재하는 CAN Protocol을 사용하고 있다. 첫 째로 ID 스푸핑, 둘 째로 서비스 분산 공격, 셋 째로 안드로이드 좀비 어플리케이션이다. 현재 자동차들은 엔진 제어나, 도어 락 제어, 그리고 핸들의 제어를 위해 수많은 ECU들을 사용하고 있다. 그리고 CAN Protocol은 신호를 Broad - Cast 방식으로 제공하기 때문에 해커들은 굉장히 쉽게 그 신호에 접근 가능하다. 그리고 차량 통신 시스템을 공격하기 위해 Android나 IOS와 같은 범용성이 높은 어플리케이션을 자주 이용한다. 차량의 소유주가 블루투스 동글을 통해 신호를 넓게 퍼뜨리게 되면 해커는 이 신호에 쉽게 접근하게 되고, 해당 데이터를 수집해 분석하고 그들은 차량의 ECU를 공격하기 위해 특정한 데이터를 만들고 ECU에 전송해 ECU를 제어하게 된다. 그래서 본인은 인증 시스템과 안드로이드의 말단에서 이러한 공격을 막을 방법을 제시한다.

• 산업공학
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• 제21권3호
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• pp.294-301
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• 2008

Agile and flexible manufacturing systems make it mandatory that a control program should have features such as agility, flexibility, and reusability in order to run manufacturing unit smoothly. PLCs are the most frequently used control program in manufacturing systems. PLC programs are mostly programmed by subcontraction, which makes correction of code very difficult. As a result, it may cause delay during down time and ramp up time which leads to big loss of revenue and goodwill. To prevent delay during the times, this paper proposes systematic process analysis and application method for programmable logic controller like LLD (Ladder Logic Diagram). The proposed method uses modified human-error investing techniques for documentation and transforming technique to program LLD from the documentation. Furthermore, this paper demonstrates an example of piston mechanism to explain the proposed method.

• 한국자동차공학회논문집
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• 제24권6호
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• pp.702-708
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• 2016

The torque converter is deformed according to the rotating speed and control pressure when engine power is transferred to the transmission. This deformation, which is called ballooning phenomenon, occurs mainly at the outer side by the centrifugal force of the automatic transmission fluid (ATF) and the control pressure from the valve body. Although the torque converter is slightly deformed when rotating, the ballooning phenomenon affects fluid performance, efficiency and durability. Thus, expansion characteristics analysis is important in determining torus size, control pressure and structure. In this paper, an analysis equation and FEM model was developed to investigate the expansion characteristics. Using this model, structural analysis was performed to investigate the relationships between deformation and the torus diameter. The results were confirmed by comparing with the test results.

• 한국자동차공학회논문집
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• 제20권1호
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• pp.112-118
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• 2012

The electronic wedge brake is one of the brake-by-wire systems with a self-energizing effect. The electronic wedge brake has faster response than the conventional hydraulic brake and requires only about one-tenth the power to operate. However, the electronic wedge brake cannot be implemented unless the self-energizing effect is reliably controlled. The self-energizing mechanisms may result in unintentional lock up and are very sensitive to environment and parametric variations of the friction coefficient. In this study, the electronic wedge brake is modeled into dynamic equations, and a sliding mode controller is designed based on the model. The performance of the proposed controller is verified in simulations.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2004년도 학술대회지
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• pp.117-122
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• 2004

In order to improve the fuel economy by design change of automatic transmission, various technologies such as increased shift stages, slip control of lock-up clutch and compact and low-weight design have been developed. And also many OEMs have developed their own ATFs as a part of these automatic transmissions. In this study. to investigate the effects of ATF characteristics on fuel economy, we got the worldwide OEM ATFs and made some reference fluids. And physical properties, frictional characteristics and fuel economy using dynamometer test for these fluids were evaluated. From the investigation, it was found that viscosities of ATFs are correlated with fuel economy in dynamometer test and reducing the viscosities made it possible to obtain fuel economy.

• JSTS:Journal of Semiconductor Technology and Science
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• 제13권5호
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• pp.459-464
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• 2013

A reset-free anti-harmonic programmable multiplying delay-locked loop (MDLL) that provides flexible integer clock multiplication for high performance clocking applications is presented. The proposed MDLL removes harmonic locking problems by utilizing a simple harmonic lock detector and control logic, which allows this MDLL to change the input clock frequency and multiplication factor during operation without the use of start-up circuitry and external reset. A programmable voltage controlled delay line (VCDL) is utilized to achieve a wide operating frequency range from 80 MHz to 1.2 GHz with a multiplication factor of 4, 5, 8, 10, 16 and 20. This MDLL achieves a measured peak-to-peak jitter of 20 ps at 1.2 GHz.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.353-356
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• 1999

A 3.3V PLL(Phase Locked loop) is designed for a high frequency, low voltage, and low power applications. This paper proposes a new PLL architecture to improve voltage to frequency linearity of VCO(Voltage controlled oscillator) with new delay cell. The proposed VCO operates at a wide frequency range of 30MHz~1㎓ with a good linearity. The DC-DC voltage up/down converter is utilized to regulate the control voltage of the two-stage VCO. The designed PLL architecture is implemented on a 0.6${\mu}{\textrm}{m}$ n-well CMOS process. The simulation results show a locking time of 2.6$\mu$sec at 1Hz, Lock in range of 100MHz~1㎓, and a power dissipation of 112㎽.

• Journal of Dental Anesthesia and Pain Medicine
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• 제16권1호
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• pp.55-59
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• 2016

Dental treatment under sedation requires various sedation depths depending on the invasiveness of the procedure and patient drug sensitivity. Inappropriate sedation depth may cause patient discomfort or endangerment. For these reasons, patient-controlled sedation (PCS) pumps are commonly used. Patients are able to control the sedation depths themselves by pushing the demand button after the practitioner sets up the bolus dose and lock-out time. Dexmedetomidine is an ${\alpha}$-2 adrenoreceptor agonist with sedative, analgesic, and anxiolytic properties. It has been widely used for sedation for its minimal respiratory depression; however, there are few studies on PCS using dexmedetomidine. This study assessed the applicability of dexmedetomidine to PCS.

• 연구논문집
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• 통권31호
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• pp.89-99
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• 2001

This paper presents the modeling and analysis of dynamic characteristics of hydraulic snubber in electric power plant. The nonlinear state-space model of 14th order to describe the dynamics of the snubber was established by Simulink. The simulation results show that the hydraulic snubber reacts as like the conventional shock absolvers against the high pulse shock load. The snubber also shows the peculiar characteristics to the small step load, which temporarily lock the control valves up, however maintain same steady-state pressures of all internal chambers in the long run. Two case studies for the analysis of the snubber are addressed. Practical pulse testing method was also proposed to identify the frequency response of the snubber.